<script>
var minute = 1000 * 60;
var hour = minute *60;
var day = hour *24;
var week = day * 7;
var month = day * 30;
function getTimer(stringTime){
    var time1 = new Date().getTime();//当前的时间戳
    console.log(time1);
    var time2 = Date.parse(new Date(stringTime));//指定时间的时间戳
    console.log(time2);
    var time = time1 - time2;
    var result = null;
    if(time < 0){
        alert("设置的时间不能早于当前时间！");
    }
    else if(time/month >= 1){
        result = "发布于" + parseInt(time/month) + "月前！";
    }else if(time/week >= 1){
        result = "发布于" + parseInt(time/week) + "周前！";
    }
    else if(time/day >= 1){
        result = "发布于" + parseInt(time/day) + "天前！";
    }
    else if(time/hour >= 1){
        result = "发布于" + parseInt(time/hour) + "小时前！";
    }
    else if(time/minute >= 1){
        result = "发布于" + parseInt(time/minute) + "分钟前！";
    }
    else if(time>30000){
        result = "发布于" + parseInt(time/1000) + "秒前！"
    }
    else {
        result = "刚刚发布！";
    }
    console.log(result);
    }
getTimer("2021-12-20 20:11:00");
</script> 


